Process for producing films or pellicles detachably secured to a paper backing or the like.



.I. BLUNDEL & A. CHOPIN.

PROCESS FOR' PRODUCING FILMS 0R PELLICLES DETACHABLY SECURED TO A PAPERBACKING OR'THE LIKE.

APPLICATION FILED JUNE 29. I9I4.

1,170,506. Patented Feb. s, 1916.

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JULES BLONDEL AND ALEXIS CHOPIN, OF RUEIL, FRANCE.

PROCESS FOR PRODUCING FILMS 0R PELLICLES DETACHABLY SECURED TO A PAPERBACKING OR THE LIKE.

To all whom it may concern Be it known that we, JL'LES BLOXDl-IL andALnxis CIIOPIN, citizens of the Republic of France, and residents inRueil, Department of Seine-et-Oise, France, have invented certain newand useful Improvemnts in Processes for Producing Films or Pellicles Detachably Secured to a Paper Backing or the like, of which the followingis aspecification.

This invention relates to an improvement in the process described in ourprevious Patent No. 1,105,243 of July 28, 1914, for the manufacture ofphotographic plates or films for cinematographic or other purposes, witha base of gelatin and more specially relates to the manufacture ofcinematographic films with perforated edges of the type commonly in usein apparatuses for taking and projecting pictures According to theformer patent, the film material, preferably gelatin is only held uponits support by the adherence of the edges during the entire period ofthe photographic operations, so as to prevent the penetration of liquidsbetween the body of the film and its support, this latter possessinginsulating portions corresponding to the edges. It is further set forththat the edges are finally cut around the plate or film'when theoperations are finished.

In the practical application of 'the process to the manufacture ofcinematographic films, certain difficulties have been experienced,because the margins of the band which are entirely made use of forreceiving the usual perforations, cannot be detached, when theoperations are finished, from the support to which they strongly adhere;moreover, it is impossible to effect these perforations in the body ofthe band. without opening a passage for liquids underneath the film, andlastly, the use of double edges is troublesome and complicates theoperation.

In accordance with our present invention and for the special applicationof the process to cinematographic films, the supporting parts destinedto receive the margins of the gelatin film are rendered partiallyadhering, that is to say, they are given an adherence just sufiicient tohold the film upon its support during the photographic operations, whilepermitting said film to be completely detached therefrom by a slightstrain when Specification of Letters Patent.

Patented Feb. 8, 1916.

Application filed June 29, 1914. Serial No. 848,066.

lVhen some other material than Wax forms the insulating material or thesupport is other than paper. the parts of the support corresponding tothe edges of the film may be coated by means of a brush dipped in anacid such as acetic acid for instance. This latter method effects acertain action upon the transparency of the gelatin and deteriorates thesame at the edge of the band, butwithout any drawback in practice,because the pictures on the film are always away from the marginal partsof the band. The partially or semi-adherent parts being thus formed uponthe support, the film material or gelatin is deposited upon the same,likewise also the emulsion. Then, they are cut into strips in the middleof the said parts in order to produce the edges in which there are thenformed the perforations in the usual manner. The taking of picture's andthe photographic processes are the same as with ordinary films. \Vhenthe operations are finished, it is only necessary to separate thephoto-type film or reproduction from its support. To this end, there maybe introduced at one of the ends of the band between the film and itssupport, a little angular piece curved, blunt and flat; on pushing inthis piece, the body of the film tends itself to carry along themargins, this separation being still further facilitated by the edges ofthe angular separator.

()ne way of carrying our process into practice is illustrated in theaccompanying drawing, in which:

Figure 1 is a front view of the film adhering at the edges to itssupport. Fig. 2 shows part of the film;separated from its support by theangulaf separator.

Asshown in Fig. 1, the film 1 is adhering at its perforated edges 2 to asupport.- Fig. 2 shows a tool or angular separator 5 having a grip 6 anda connecting piece 7, in the act of sei'iaratine; the film 1 adheringwith its perforated edges '3 to the perforated support 8 for the same,while the middle part ol the film 3, is not adhering to said support.

Having now partieuliulv described and ascertained the nature of our saidinvention. we declare that what we claim is:

1. Method of making einematographie films having pert ratededgesronsistine in coating: the support for the gelatin film with anon-adhesive material then treating near the edges thereof with aneutralizing agent for the non-adhesive material hetween support andfilm in such a manner that not more than a mere weak adhereuee ol' theiilin to the support is produred at its edges, sulliciently weak toadmit of its being easily stripped from the support.

Method of making einematographie machines having perforated edges,consist ing in coating the support for the gelatin film with anon-adhesive n'iaterial, then treating near its perforated edges withacetic acid adapted to deteriorate the non-adhesive emulsion betweensupport and film to such a degree that no more than a mere weak adherenee of the lilm to the support at its edges is produced sullieienttvweak to admit of its being easil stripped from the support.

In testimony whereol' we allix our signa tures in presence of two\\'itnesse JI'LCS BLUXDEL. ALEXIS (HOPIN \Yitnesses:

("n.\s. l. lmzssgn, EDWARD Wow.

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